[Not Applicable]
[Not Applicable]
1. Field of the Invention
The invention relates to fire extinguishing devices. In particular, this invention relates to a device that disperses fire-fighting chemical agents, both wet and dry types, through the use of an explosive force.
2. Background of Prior Art
Fire-fighting devices in general use at present, are subject to numerous limiting factors with respect to their cost of acquisition, placement, storage, deployment for fire-fightingxe2x80x94or fire suppressionxe2x80x94and other factors. By their nature, they may require periodic inspection by qualified, knowledgeable persons, training or esoterically detailed familiarity in their use, are typically bulky and/or require, as centralized sensing and extinguishing systems, extensive, expensive installation to afford the protection they are designed to provide.
Small fire safety devices, such as the common pressurized dry chemical extinguisher, are relatively heavy, due to the prerequisite construction of the their pressurized containers. Their weight, bulk and relative complexity, adds to the cost of manufacture, and therefore, theoretically, their cost of acquisition. In use, their directed stream of chemical spray requires judgment and forethought, and therefore, a fully conscious and cognizant user whose mental faculties have not been impaired by smoke, heat, mental stress or panic.
Sprinkler systems, are subject to high installation costs, and may fail to effectively fight fires due to limited water supplies, sedimentary clogging of water supply piping, or failure to install sprinkler heads with sufficient coverage areas throughout an edifice, among other factors.
A drawback to nearly any fixed installation of fire-fighting equipment such as fire hoses, sprinklers, or the device of U.S. Pat. No. 6,056,063 to Hung, is that they are often installed with less than complete coverage area for the full extent of the interior space they were installed to protect, due to limits of the dispersal pattern from the fixed mounting, or physical obstructions to retardant discharge. An example being a single dispersal unit, such as a water sprinkler head, in the center of a hotel room, which if actuated due to fire, would have a dispersal pattern which might not reach all corners of an irregularly shaped room, such irregularities commonly including short entrance corridors and closets blinded from the sprinkler head by corners, etc.
Thus, the present invention is designed as a product which is versatile in installation mounting, i.e., mountable in a simple holder on walls, desk, counter or table surfaces, or elsewhere, and be able to self-actuate when situated as thus, yet can be lifted out of its holder and deployed manually, should any occupant of the room or area deem appropriate, and be conscious and capable of doing so.
Explosive devices for fire-fighting purposes, in prior art, have often demonstrated high efficiency in extinguishing localized blazes, but have shown limitations, again, in cost and the relative sophistication of their design impacting complexity in manufacturing process. Also their methods of storage, deployment and/or use, such designs may be seen to require expert use, inhibiting broad public acceptance. Again, as mentioned previously, dispersal patterns of the fire extinguishing chemicals from some explosive fire-fighting devices may, in some cases, be less than uniform or ideal. Two other important detractions to explosively dispersed chemical fire-fighting devices are the force of detonation experienced with some, and subsequent flying debris from even some minute parts of such devices despite frangible casings, therefore being, therein, safety hazards unto themselves.
In nearly all prior art, be they of explosive type or other means of delivery, the cost of manufacture and/or installation, and therefore the cost of purchase is a limiting factor to broad public demand; this factor being most acutely apparent in underdeveloped countries, and even in poorer communities of developed nations.
The bulk and subjective unsightliness of even the common dry chemical, pressurized tank fire extinguisher aesthetically limits their installation in many private dwellings worldwide. One does not typically find such devices mounted in living rooms, or guest reception areas, sometimes purely for aesthetic reasons.
Frequently, only one fire-extinguisher is maintained for the entirety of a private dwelling, and it may fail to work after lying dormant many years, due to its need of periodic inspection and maintenance by qualified personnel; something often overlooked by private owners. And with only one fire-fighting device deployed at some point within the dwelling, the possibility exists that a path to it may be blocked by flame and/or smoke, especially when a fire starts and spreads while the occupants are asleep.
The present invention is intended to overcome or lessen the above limitations in prior art.
1. Object of the Invention
The object of this invention is to provide an inexpensive, compact and easily used device, which, while being of the explosive type, does not present any serious safety hazard in its actuation.
It is important to establish in this portion of the disclosure that the present invention is a single-use device, which is environmentally friendly in its basic construction, and leaves little more residue than the expended fire extinguishing/suppressant chemicals employed with the device, when actuated. No attempt is made to affect reusability in the device, because a reusable device requires components that can withstand the stresses of a remanufacturing process, add the need for a recycling infrastructure that can not only xe2x80x98refillxe2x80x99 the device, but also test and certify that the recycled device can perform again at the required level of protection or usefulness. This of course leads to the requirement that the reusable components must be sturdy enough not only for refilling/remanufacturing, but to be able to reliably perform for more than one use. These preconditions to a reusable device, especially with respect to a device upon which lives and property would depend, it is felt economically prejudices reusable containers or systems for general public use.
What is logically required in a low-cost, easily manufactured, effective fire-fighting device is, a low mass, inexpensively manufacturable containment vessel, with a maximum of fire-retardant chemical agent within such a devicexe2x80x94viewed as a high relative percentage of weight/mass of the fire-fighting agent to the total weight of the complete functional unitxe2x80x94and a method of dispersal of the chemical agent by a rapid means, which in itself is lightweight, does not create bulk, is inexpensive and places few demands on the device container while the device is stored and unused. General public acceptance also requires other values, as well, those being that it is highly effective in its work, that it is intuitively easy to use, compact enough to be placed anywhere near at hand when needed, and that it be inexpensive.
Thus, the device disclosed herein is intended to have the following featuresxe2x80x94
A simple, self-contained design, and of a construction whose physical integrity and ability to operate can be quickly surmised through visual inspection of its exterior by ordinary persons not highly versed in technical knowledge, and bexe2x80x94
inexpensive and easily manufactured in nearly any country, worldwide;
so intuitively simple in its use that even a confused or partially impaired user may employ it with little forethought;
so innocuous in size and shape that it may be installed or stored in nearly any environment without esthetic objection;
capable of actuation with or without human intervention, and if without, that upon detonation provides sufficient aural report to warn persons in the vicinity of the fire threat.
2. General Description
The present invention is an explosive, fire-fighting device comprised of three basic components, beingxe2x80x94
a) A frangible casing whose composition represents no threat as shrapnel,
b) Fire-fighting agents such as are commercially available, whether being either dry, wet, or of other form in single or multiple component combinations,
c) A detonating device with low explosive yield, insufficient to deliver a debilitating concussive shock to humans at even relatively close proximity to the device during actuation, preferably of a type lacking any constituent part with sufficient hardness, mass or density to constitute shrapnel-like hazard, and be commercially available and commonly found.
In the preferred embodiment, component a) is comprised of a low-density, rigid plastic foam molded to shape, which may be, but is not limited to, a spherexe2x80x94comprising one hemispherical molded shape, where two of the same molded part form a complete sphere, which again, is not intended to limit the present invention to only one shape, nor exclude other possible configurations of the casing.
If the seam formed by the assembly of two such hemispheres together may be considered a latitudinal plane of reference, then at the polar regions of the component hemispheres, or other convenient point(s), small holes are located with adjacent exterior surface cavities through which small pyrotechnic fuse cords are protruded and laid flat in the aforementioned cavities. A round filler hole molded into the hemispheres at the joint between them suffices as an orifice for charging the device with the chemical fire-fighting agent(s) after assembly of the casing halves into a whole unit with the detonator already inside.
The wall thickness of a rigid foam casing has been found to be adequate at between 0.8-1.0 centimeter, for a device approximately fifteen centimeters in diameter. An adhesive compatible with the casing material may be employed in assembling the two casing halves, but is not essential.
Surrounding the assembled casing, as outer layers, are typically one or more layers of commonly available, moderate thickness, plastic shrink-wrap film. In the spherical exterior embodiment of this device, the first layer would be a wide band of the shrink-wrap film applied in a vertical orientation, crossing the poles of the sphere, holding secure the two hemispheres, as well as the filler plug, and also covering the fuse ends at the poles. This layer, after low temperature hot air is applied to the shrink-wrap film, covers most of the sphere. A second band, being the same partxe2x80x94in size, thickness and diameterxe2x80x94as the first layer, is applied latitudinally about the seam formed by the two assembled halves. When the second band is heat-contoured to the sphere, the layers together completely cover the exterior of the invention. The shrink-wrap film layer(s), no matter what the external shape of the device is, can provide the structural quality which typical low-density, rigid plastic foam materials for the casing lack, i.e., a tensile external xe2x80x98skinxe2x80x99 more resistant to surface abrasion. This sheathing also helps to make the invention highly water-resistant, where desired, with the additional modest application of silicone-based, or other, sealants in a few selected areas.
Component b) is the primary, and possibly secondary, fire-extinguishing agent. The choice of chemical agent is limited only to that the core chemicalxe2x80x94meaning the chemical charge in a single walled version, or the inner core charge of the multi-walled version of the present inventionxe2x80x94should be of the dry powder type, such as of commercially available ammonium phosphates or sodium carbonate types, or any other suitable fire-fighting chemical in dry powder form; otherwise the detonator must be impervious to the agent in any other physical form, or the detonator be isolated from the chemical agent through protective wrapping or coating.
The choice of chemical agent is determinable by availability, cost and intent to specialize a version of the present invention for a particular type of fire hazard.
Liquid or even gaseous agents at atmospheric pressure may otherwise be accommodated by adding them to the outer cavity, or cavities, of a multi-walled construction, with outer casing(s) essentially much the same construction as the inner casing, only larger. It has been found that even plain water affords a marked increase in fire-fighting efficacy as an instantaneous coolant, through misting, upon detonation of the device, though other commercially known, specialized liquid agents may provide higher, specialized efficiency.
Component c) is the detonator with fuse cords at either end. These common, commercially available pyrotechnic detonators are typically of the magnesium/aluminum powder-based type, and are chosen for wide availability, in sizes with only just enough explosive yield to burst the casing(s) of the device, and disperse the fire-extinguishing agents in an effective pattern.
A small, fifteen-centimeter diameter, single component, dry chemical device of this invention has been found to be capable of dispersing its chemical agent up to two meters, or more, from the point of detonation, in an omni-directional dispersal patternxe2x80x94given the preferred spherical exterior configuration, and can effectively achieve effectively spontaneous dousing of flames within that radius for many types of fires, without the need of much explosive force. It has also been found that the force required to disperse dry powder chemical cores in a fifteen-centimeter diameter device of this invention will in most cases cause only slight temporary bruising to bystanders at a stand-off range of 0.5 meters or less, and be very unlikely to cause any permanent injury even if in direct contact with the device during detonation, depending on variations in actual construction and moderation in choice of detonator yield.
This is due to the fact that the container, or casing, of the invention is made from the foam frangible material with sheathing as previously disclosed. While this configuration is sturdy enough to sustain the physical integrity of the device against moderate external physical abuse, and permitting a long shelf life, the force required to shatter it from within and disperse its chemical agent(s) is not great.